When the car is both cold and hot it will struggle to start from time to time, when i say struggle i mean i am turning the key for around 6 to 8 seconds (when its playing up at its worst) waiting for it to catch? Another thing it seems to be doing also is suffering from erratic idling, the rev counter will bounce between 800rpm and 600rpm with the engine sounding like it's missing. Its been serviced around 700 mile ago with PD oil and a new air, oil and fuel filter by a good mechanic i know. The car is a 56 plate 2.0L TDI 140, manual with 50K. This is the from this morning, as you can see the glow plug light has already gone out and it still struggles to catch and fire.